Distal anterior cerebral artery aneurysms.

BACKGROUND Distal anterior cerebral artery (DACA) aneurysms, also known as pericallosal artery aneurysms, represent about 6% of all intracranial aneurysms. They are located on the A2-A5 segments of the anterior cerebral artery and on its distal branches. METHODS This paper summarizes present knowledge on radiological features, treatment options, treatment results, and long-term follow-up of DACA aneurysms. FINDINGS Typical features of DACA aneurysms are small size, broad base, and branches originating from the base. When ruptured, they cause intracerebral hematoma in nearly half of the cases. DACA aneurysms are nowadays more often treated with microsurgical clipping than endovascular coiling due to their distal location and morphologic features. With clipping the results are same or slightly better than for aneurysms at other locations, coiling is often associated with more complications than in other aneurysms. CONCLUSION Clipping is a long-lasting treatment with very small recurrence rate, there is no long-term data available on efficacy of coiling yet. For ruptured DACA aneurysms the most important factors affecting outcome is the severity of initial bleeding and patient's age.